Part$1$:

Use Logisim to implement a $4$ bit ALU circuit that can execute the following instruction set:

Use gates to implement adders

Use Multiplexers $($any size you need$)$

Use the hierarchical modeling in Logisim

FlarrA

FlarrA$+1$

FlarrA$+B$

FlarrA$+B+1$

FlarrA$\frac{+}{b}ar(B)$

FlarrA$\frac{+}{b}ar(B)+1$

FlarrA$-1$

FlarrA

$Flarr{A}^{{?}^{?}}B$

Logic

FlarrAvvB

FlarrAo$+B$

Flar$\frac{r}{b}ar(A)$

FlarrB

Shifting

FlarrsrB

FlarrslB

Part $2$:

For the ALU designed in Part $1,$ you need to interface the ALU with a RAM system. The RAM can be used directly in Logisim. You do not need to build it yourself.

This means your system now should execute instructions where the operands can come from Memory and the output can be written to Memory.

The following are the factors to evaluate the projects:

Design $(80\%)$

a$.$ Interface of RAM through Read and Write operations

b$.$ Data transfer from Memory to ALU

c$.$ Correct results of functions in RAM and on output ports

d$.$ Instructions should include: Register to register operations, Memory to memory operations, immediate to memory operations

Optimal layout $($Minimum number of components, modular design, hierarchical representation$)(20\%).$